Problem: Simplify the following expression: $n = \dfrac{1}{9p} + \dfrac{-10}{9p}$
Since the expressions have the same denominator we simply combine the numerators: $n = \dfrac{1 - 10}{9p}$ Combine like terms: $n = \dfrac{-9}{9p}$ Simplify by dividing numerator and denominator by 9: $n = \dfrac{-1}{p}$